The National Renewable Energy Laboratory has completed its analysis of UPS's first generation hybrid diesel delivery vans, finding a 28 percent fuel savings.
UPS has been pleased enough with the vans that it has ordered an additional 200 units, according to a press release.
The NREL, which is a division of the Department of Energy, measured the fuel economy, maintenance and other performance data from the vehicles, which are powered by a hybrid system from Eaton Corp.
The hybrid vehicles achieved 13.1 miles per gallon, compared to 10.1 mpg for the conventional diesel vans (see image).
Maintenance of the hybrids cost 8 percent less per mile than for the diesel vans.
However, the hybrid vans came with some bugs. The hybrids had a cumulative uptime average of 95.5 percent, compared to 99.3 percent uptime for the conventional vans.
The 12-month test encompassed the operations of six of these vehicles at a UPS facility in Phoenix. Read the full report here (PDF).
Development of the Eaton hybrid system was funded in part by $7.5 million from the Department of Energy.
UPS has experimented with other forms of hybrid trucks, including a hydraulic hybrid system that uses a Freightliner custom chassis and hydraulic hybrid system from Parker Hannifin Corp.
Meanwhile, Coca-Cola Enterprises has deployed hybrid-electric tractor-trailers in its Ohio operations, according to a press release.
The trucks, which can haul a gross vehicle weight of 55,000 pounds, feature 30 percent improved fuel efficiency when compared to standard tractor trailers.
Coca-Cola Enterprises is on track to add 185 hybrid-electric trucks in 2009, bringing its total hybrid-electric fleet to 327, which it says is the largest in the U.S.